Distribution:
Appears to be endemic to southwestern Borneo though occurance records are scant. The type locality is ‘Bandjarmasin’, a port town in the Indonesian province of Kalimantan Selatan (South Kalimantan), and following Kottelat (1991) it’s range extends westwards as far as the Jelai Bila river basin, near the town of Sukamara, where it’s said to occur sympatrically with the congener B. merah (but see ‘Notes’).
Habitat:
Inhabits black water streams and pools associated with ancient forest peat swamps. The water is stained brown due to the release of tannins and other chemicals released by decomposing organic matter and the substrate scattered with fallen leaves, twigs and branches.
Such environments characteristically contain very soft (negligible hardness), acidic (pH as low as 4.0) water and are often dimly-lit due to dense marginal vegetation and the forest canopy above. Across much of Southeast Asia these precious biotopes are under threat from rubber or palm oil plantations, building developments and other human activities.
Water Conditions:
Temperature: 20 – 28 °C
pH: 4.0 – 7.0
Hardness: 18 – 179 ppm
Reference:
https://www.seriouslyfish.com/species/boraras-brigittae/